wheeler



A. S. WHEELER ESCAPEMENT MECHANISM FOR TYPEWRITERS Jan. 17, 1928.1,656,460

Filed May 28. 1926 2 Sheets-Sheet 2 fyi WITNESS BY i *M11* latented .lam17, 1928.

unirse stares `.FJQELTIIUR S. VIHEELER, NEWT YORK, N. Y., A SSEGNOR, BYMESNE ASSIGNIVIENTS, TO

vnnrrrrnn, rnconzeonarnn, a

CORPORA'EON i OF EJELAWARE.

ESCAPEMIENT MECEANSM FOR TYPEVTRETERS, y

Application filed May 28,

This invention relates to escapement mechanisms for typewriters and hasfor its primary object to provide improved power connections for anescapement shaft for controlling,r the movements of typewriter-carriagessuch,\for example, as thosel employed in the Hammond typewriter.

One of the objects of the present invention is to provide a motor ofimproved construction whereby power may be applied to the escapementmechanism and related parts other than that derived from the motor whichdrives the carriage.

Another object of my invention is to provide improved winding mechanismfor the auxiliary motor.

Other and further objects of invention will appear in the specificationand be pointed out in the appended claims, reference being had to theaccompanying drawings which show my invention in a preferred embodimentand in an adaptation to a Hammond typewriter.

In the drawingsf Figure 1 is a top plan View of myimproved motor andself-controlled winding mechanism in connection withy related parts of aHammond typewriter, parts being broken away and parts shown in section;y

Figure 2 is a section on the line 2 2, of Figure 1;

Figure 3 is a section on the line 8'-3, ol Figure 2;

Figure i is a section on the line 1-4, of Figure 1; i

Figure 5 is a section on the line--\, of Figure 1, parts being brokenaway and parts shown in section; Y 1 t Figure G is a similar section ofsome of Jthe parts shown in Figure 5 in changed posiu tions and withfragmentary portions of the spring-motor housing` and driving connections shown alcove; and

Figure 7 is a fragmentary section taken on the line 7-7, of Figure 6. c

Be'lerringq more particularly to thedrawlings, the typewriter frame 1 isprovidedwith an upwardly presented lug` 2 shown in dotted lines inFigure Vithin this lug` is journalled the rear end of an escapementshaft 3 to which the letter-space movements of the carriage aretransmitted. Thus, re- 'fer-ring to Figures 1 and 5ol the drawings, umain carriage-driving motorI 100 is provided with a spring-driven gear101 which ieee. serial no. 112,364.

meshes into a rack-bar 102 {represented by broken lines)` mounted on thecarriage. Meshing with said rack-bar 102 and driven thereby .is a spur103 which is rigidly connected tol sleeve 104 which is freely journalledupon escapement shaft 3 and carries a ratchet 105. A pawl 10G isoscillatably mounted upon a stud 107 carried by a disc 108 and is heldin engagement with said ratchet by means of a spring 109 which issecured at one end to a stud 110 carried by the disc 108. Said disc 108is provided with a hub-portion 108L which is non-rotatably connected toan escapement ratchet-wheel 5. For this purpose, said disc .108 andratchetwheel 5 may be keyed to the shaft 3 or these parts maybe rigidlyconnected` together by a common sleeve and freely j ournalled upon saidshaft 3. The ratchet wheel 5 is adapted to be engaged by apawl 6 pivotedat 1' upon a hammer-constraining lever 8, said lever being` freelypivoted onthe escapement shaft 3 and provided with a bent ltaillever 9which as shown in igure -1 is provided with an enlargement 10 whichmoves upwardly` and downwardly upon a stud 11 which, as shown in vFigure5, may be locked in any suitable position by a set screw 12, the lowerposition of a hammerbar 13 being thereby determined. nasmuch as thespring-pressed pawl 106 is included in the driving,` connection betweenthe carriage-driving motor and the es-l capement shaft 3, a return orretrograde movement` of the carriage is provided for without aCorrespending` movement of said escapement shaft 3. As-shown in Figure5, an escapement beam 14- which oscillates on a pivot 15, carries an arm16 provided with a slot l? within which is disposed a pin 18 carried bythe pawl 0 and by means of which said pawl is moved into and out ofengagementwith ratchet 5. A detent 19 mounted in one arm of the heam11i, is adapted to en-` gage the teeth of ratchet 5 as pawl (i isretracted from said ratchet. The foregoing` parts are in general use onthe Hammond typewriter at the present time.

Ey an inspection of Figure 5, it will lbe understood that whenever atypewriter key is depressed, the resulting clockwise oscillation ofescapement beam 'lll operates to retract the pawl t3 from engagementwith ratchet 5. This movement thus releases the hammer-operatint,1rlever 8 and permits the actuation of the hammer bar 13m a wellknownmanner. At the saine time, the detent 19 is moved into engagement withratchet which however is in'imedia-tely disengaged therefrom by thereturn or counter clockwise movement of escapement beam l-l whichreturns the pawl 6 to ratchet-'engaging position and thus serves toapply power from ratchet 5 to lever S for retracting hammer bar 13 tonormal position.

As heretofore constructed, typewriting machines of the Hammond type inwhichthe escapeinent mechanism has derived its power solely from thespring motor which drives the paper-carriage, it has been necessary toprovide an excessively heavy tension in the spring of said motor inorder to supply the required amount of power for returning the hammerbar to normal position after each oj'ieration thereof. Such aconstruction has heretofore made necessary a heavier carriage as well assturdier operating connections therefor.

According to my improved construction shown and described in the presentapplication, it becomes possible to employ a lighter carriage and lesstension in the spring motor which drives the carriage so that a lighterrunning and more easily eperated'machine made possible. For thispurpose, l employ the auxiliary power mechanism now to be described.

Mounted upon the rearmost end of yescapement shaft 3 is a spur gear '2Owhich meshes into a larger spur gear 2l, sai larger gear being securedto the drive shaft 22 of an auxiliary motor by means of a setscrew 28.The essential purpose of this auxiliary motor resides' in the provisionof suitable power outside of the carriage drivingmotor for retractingthe typing hammer after each typing operation. By means of thisprovision it becomes possible to employ a carriage-driving motor of lesspower and lighter action so that the return or retrograde movements ofthe carriage can be had more expeditiously and with less effort. Asshown inv Figures l, Il, and 5, said drive shaft 22 is journalled inoppositely arranged plates or frames 24 which are rigidly secured to thetypewriter frame l. Journalled upon an enlargement 25 of the shaft 22 isa housing 26 within which is disposed a coiled spring 27. The inner endof said spring is secured at 28 'to said enlargement 25, the outer endof said spring being secured by a screw 29 to the peripheral wall of thehousing 26. Said housing is provided with a circular rack 30 with whichmeshes a worm screw 3l. As shown best inFigures l and 6, the worm screwis carried by an extension 32 of an Aarmature shaft 83 yof an electricmotor 34, said extension 32 being yieldably conpin 35 which during acontinued step by step movement of spur gear 2l, is brought intoengagement with an arm 36 of a star wheel 37, said star wheel beingsecured to a rotary shaft 38 by means of a set screw 39. The shaft 38 isjournalled at opposite ends in the frames 2e' as shown best in Figure 2.As shown in the preferred embodiment, the star wheel carries four armsof which the two oppositely presented arms 36 are arranged adjacent tothe path of pin 35 as it revolves with gear 2l. The other two arms 40project substantially at right angles to the arms 36 and are axiallyspaced therefrom so that their revolving movements bring them into thepath of pin fil which projects forwardly from the lateral wall of springhousing 2o. As shown best in F igures 5 and t3, a leaf spring 42 whichis secured to cross bar by means of a screw 4e, iskpresented upwardlyinto position to interlock yieldably with any one of a series of starpointed cam arms l5 which are secured to the shaft 38 in such a way asto lock said shaft in posit-ion when not positively engaged by one orthe other of pins 35 and 41.

Referring nowto Figures 2 and 3, the shaft 38 is provided at one endwitha diainetral slot through which passes a metal strip 46, the outer ends47 of said strip being bent around on the periphery of the reduced endof shaft 38 to adapt said strip to bridge the space between oppositelyarranged spring contacts i8 in every other position of the star wheel37. Secured to the spring contacts d8 are wires 49 which, as indicatedin Figure l, are contained in a cable 50, said cable having a branch 5lleading to motor 34. lt is-obvious, therefore, that whenever vthe strip46 is in circuit-closing position, the

motor 34 will be energized and the spring 27 will be wound. The cable 50may be provided with suitable socket connections whereby the motor 34may be connected up with an ordinary lamp socket.

lt will be understood from the above description that as the escapementmechanism is operated step by step during the use of the typewriter, thespring 27 is transmitting power to the drive shaft Q2 in such a way asto enable the employment of a weaker spring upon the carriage of thetypewriter and thus provide a lighter action of the carriage without inany way adversely affecting the typing action. it will be understoodthat as the pin 35 revolves, the star wheel 3T will be rotated intoposition to close he circuit through motor 3a and as the spring QT iswound up, 'the pin ll carried by the housing 26, will impart a furthermovement to star wheel 37 which action brealc'y the circuit of motor 3a.

Referring now to Figure l, an interlocking arm 52 is loosely mountedupon the Ell) drive shaft 22, said arm being provided with a laterallypresented linger 53. As shown in Figure 7, a bent plate 5a is secured.by a stud 55 to the gear 2l, the outwardly deflected edge of platefrbeing adaptedto engage the linger 53 during rotation oi gear 21.Projecting laterally from the wall'o't' housing 2G` is a pin 5G which,when the motor is deenergized, constitutes a fixed stop. It may be seen,therefore, that if at any time, the curernt is'completelv cut off frommotor 34 yfory a suliicient length of time during the use oli thetypewriter, the bent plate 54 will be revolved by the movement of gear2l until it comes into engagement with the radial arm 52 which will berevolved until it comes into the position shown in Figure 6 in which itabuts against the stop pin 56. The advantage of this device will be seenin the event, for example, that the current having been turned oli atthe lamp socket, such as may occur at night, a subsequent use of thetypewriter' may take place without the switch being turned to closedposition, whereupon the operation just described wouldtake place.

I claim l. In a typewriter,.the combination with a carriage-drivingAmotor, ot escapement mechanism connected thereto, a hammer-4constraining lever connected to said escapement mechanism, and anauxiliary motor connected to said hammer-constraining lever through saidescapement mechanism.

2. In a typewriter, the combination with a carriage-driving motor, ofescapement .n'iechanism connected thereto, a hammer-ccnstraining leverconnected to said escapemeut mechanism, an. auxiliary motor connected tosaid hammer-constraining lever through said escapement mechanism, and`means under the control 01"' said auxiliary motor for reenergizing thelatter.

In a typewriter, the combination with a hammer-constraining lever, ofcarriageescapement mechanism including a ratchetwheel, a spring motorgeared to said ratchetwheel, said spring motor comprising arotary shaft,a rotary housing coaxial with said shaft and a coil spring having itsopposite ends secured to said rotary shaft and housing respectively, apawl mounted on said lever and engaging said ratchet-wheel, means tormoving said pawl into and out of engagement vwith said ratchet, andmeans under the control of said rotary shaft and housing for rotatingthe latter.

In a typewriter, the combination with a carriage-driving motor, ol acarriage-rack geared thereto, a hammer-constraining lever, escapementmechanism connecting said rack to said hammer-constraining lever, and anauxiliary motor connected to said hammerconstraining lever through saidescapement mechanism.

y5. In a typewriter, the combination with an escapement shaft, ot avibratory'lever, a

hammer `connected to said lever, escapement mechanism for controllingthe escapement movements otsaid sha-tt, said iescapement mechanismincluding a pawl and ratchet connection between said shaft and lever, amotor geared to said escapement shatt, an electric motor geared tothefirst-mentioned motor, an energizing circuit tor the secondmentionedmotor including a `switch for making and breaking the energizingcircuit,

a star-wheel for operating said switch, and,

means operated by the hist-mentioned,motor fior imparting a step by stepynnwement to said star-wheel.

6. In a typewriter, the combination with an escaeement shaft, ollacarriage-driving motor, a one-way driving connection between said motorand shaft, a lever oscillatable about the axisot said shalt, a hammerconnected to said lever, a ratchet keyed to said shaft, a pawl pivotallyconnected to said lever und operatably engaging said ratchet, ancf-xfapement beamy controlling the escapement movements of said shaftand` moving said pawl into and out of engagement with said ratchet, saidpawl when disengaged from said ratchet being adapted to permit theprinting stroke ot said hammer, and when thrown back into engagementwith said ratchet to retract said lever and hammer to normal position,and an auxiliary motor geared to` said escapement shaft independ-` whensaid housing and shaft reach a predetermined position in their relativerotation.

8. Ina typewriter, the combination with an'escapement shaft, et acarriage-driving motor, a ratchet-drive connection between said motorand shaft, a hanimer-returning lever oscillatable about the axis of saidshaft, a ratchet wheel keyed to said shaft, a pawl pivotally connectedto said lever and operatably engaging said ratchst-wheel. an escapementbeam controlling the cscapement movements of said shaft and moving saidpawl into and out ot engagement; with said ratchet-wheel, said pawl'when in Vinigagement with said ratchet-wheel being adapted lo restrainthe hammer vfrom its printing stroke and when. disengaged from saidratchet-wheel to permit the fainting stroke oir said hammer, and anauxiliary motor geared to said escapement shattindependently of saidratchet-drive connection and adapted to supplement the powerI applied tosaid shaft by the carriage-driving motor.

9. In a typewriter, the combination with an escapement shaft, of aspring motor comprising a drive-sliaft provided with a gear geared tosaid escapement shaft, a rotary housing coaxial with said drive-shaft, acoil spring arranged in said housing and having its opposite endssecured to said drive-shaft and housing respectively, an electric motorhaving an armature shaft geared to said housing, a switch for saidelectric motor, a star-wheel for operating said switch, a pin carried bysaid drive shaft gear for operating said star-wheel, and a pincarried'by said housing for operating said star-wheel.

l0. In a typewriter, the combination with an escapement shaft, of aspring motor ccmprising a drive-shaft, a gear keyed to said drive-shaftand geared to said escapement shaft, a rotary housing coaxial with saidshaft, a coil spring arranged in said housing and having its oppositeends secured to said rotary shaft and housing` respectively, an electricmotor having an armature shaft geared to said housing, a switch for saidelectricfmotor, means operated by said gear and rotary housing foroperating said switch to start and stop said electric motor, a laterallypresented stop pin carried by said housing, a laterally-projectingstop-plate mounted on said gear, and an arm movable on said drive-shaftand interposable between said stop-pin and stop-plate for locking saiddrive-shaft.

1l. In a typewriter, the combnation with an escapement shaft, of aspring motor comprising a rotary shaft geared to said escapement shaft,a rotary housing coaxial with said shaft, a coil spring arranged in saidhousing and having its opposite ends secured to said rotary shaft andhousing respectively, an electric motor having an armature shaft gearedto said housing, a switch for said electric motor, means operated by the`rotary shaft of said spring'motor for operating said switch to startsaid electric motor and by said rotary housing for stopping saidelectric motor, said armature shaft comprisng yieldably sections.

l2. In a typewriter, the combination with a carriage-driving motor, ofan escapement shaft, means including a pawl and ratchet connectionforconnecting said motor to said shaft, a vibratory hammer-constraininglever, escapement-control means including a releasable connecton betweensaid shaft and lever, and auxiliary power means geared to saidescapement shaft independently of said pawl and ratchet connection.

13. In a typewriter, the combination with a carriage motor, of anescapement shaft, a

connected Lceaaeo one-way driving connection between said motor andshaft, a lever pivoted on said shaft, a ratchet wheel keyed to saidshaft, a pawl pivotally connected to said lever and normally engagngsaid ratchet-wheel, an escapement lever movably engaging said pawl, adog movable by said escapement lever intoA and out of engagement withsaid ratchet-wheel, auxiliary power means geared to said escapementshaft, independently of said one-way driving connect-ion, and a hammerconnected kto the first-mentioned lever and returnable to normalposition by said ratchet when sald pawl is thrown into engagement withsaid ratchet.

la. ln a typewriter, the combination with a carriage-driving motor, ofan escapement ratchet-wheel, means including a one-way drivingconnection for connecting said motor to said ratchet-wheel, a typinghammer, means including a pawl which releasably engages saidratchet-wheel for connecting said typing hammer thereto, an escapementbeam movably engaging said pawl and carrying a ratchet. dog for engagingsaid ratchet at times when said pawl is moved out of cngageinenttherewith, and an auxiliary motor geared to said ratchet-wheelindependently of said one-way drying connection.

' in a typewriter, the combination with a carriage-driving motor, ofescapement mechanism therefor, means including a oneway drivingconnection for connecting said motor to said escapement mechanism, atyping hammer operatably connected to said escapement mechansm, and anauxiliary motor connected to said escapement mechanism independently ofsaid one-way connection.

i6. ln a typewriter, the combination with the racl of a reeiprocatorycarriage, of a carriage-driving motor, a vibratory vhammeroperatinglever, an escapement ratchet-wheel, a mechanical train including a pawland ratchet connection for connecting said rack to said ratchet-wheel, apa'wl pivotally mounted on said hammer-operating lever and operatablyrelated to said ratchet-wheel, a ratchet-dog .for engaging said ratchetalternately with said pawl, means for moving said pawl and dog into andout of lengagement with said ratchet-wheel, and an auxiliary motorgeared vto said ratchet-wheel.

17. ln a typewriter, the combination wth an escapement shaft, of acarriage-driving motor, means for connecting said motor to said shaft,escapement mechanism connected to and controlling the escapementmovements of said escapement shaft, a hammer-operating lever, anauxiliary motor, and means including portions of said escapementmechanism for connectng said auxiliary motor to said hammer-operatinglever.

ARTi-UR S. VHELLER,

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